The present invention relates generally to saving data upon loss of power, and more specifically, to sizing a write cache buffer based on parameters related to carrying out this emergency data save procedure.
Computer systems may use a storage controller as an intermediary between a host processor and permanent storage such as a disk subsystem. The host processor sends read and write transactions to the storage controller, and the storage controller in turn issues read and write commands to the permanent storage subsystem. A typical storage controller implements a write caching policy so that a write transaction is not always immediately passed on to the permanent storage subsystem, but is instead written to a write cache allocated from volatile storage such as dynamic read access memory (DRAM). At a later point in time, the storage controller issues a command to write the data from the write cache to the permanent storage subsystem.